Question

Outline completely and thoroughly the process of Cellular Respiration including where the steps occur, inputs and outputs, chemical reactions that take place, how the parts connects etc.

Answer 1

Cellular respiration involves 4 steps

1 Glycolysis

2 Puruvate oxidation

3 Krebs cycle

4 Electron transport chain and oxidative phosphorylation.

Glycolysis occurs at all the cells in the body especially in tissues lacking mitochondria like erythrocytes, cornea, lens etc.

Krebs cycle occurs in mitochondrial matrix.. Pyruvate oxidation and electron transport chain also occur in mitochondria.

Glucose is converted to pyruvate by glycolysis. Pyruvate cannot directly enter into krebs cycle hence it is converted to acetyl Co A by enzyme pyruvate dehydrogenase . Acetyl Co A enters krebs cycle and condenses with oxaloacetate to form first compound citrate.

Electron transport chain generates NADH for glycolysis and krebs cycle to occur. Thus all the steps are interlinked in cellular respiration.

The energetics of cellular respiration and net ATP generation is shown in 1st pic.. Chemical reactions of all the cycles are shown in subsequent pics.